A goblet contains $9$ red balls, $5$ green balls, and $11$ blue balls. If a ball is randomly chosen, what is the probability that it is not green?
Solution: There are $9 + 5 + 11 = 25$ balls in the goblet. There are $5$ green balls. That means $25 - 5 = 20$ are not green. The probability is $ \frac{20}{25} = \dfrac{4}{5}$.